Enhanced charge transfer via NH 2-MIL-125@ NH 2 /H-MIL-125 hetero-frameworks for photocatalytic H 2 evolution

The efficient transfer of photogenerated carriers is essential to the photocatalytic H 2 evolution. Herein, we designed and synthesized a kind of novel NH 2 -MIL-125@NH 2 /H-MIL-125 hetero-frameworks with nanopore structure to drive efficient charge transfer for photocatalytic H 2 evolution. Single-ligand NH 2 -MIL-125 (NM) and dual-ligand NH 2 /H-MIL-125 (NHM), which have similar composition, structure and well-matched energy band, were selected as the core and shell to prepare the NM@NHM hetero-framework as a proof-of-principle system. The hetero-framework strategy is proposed to intensify the charge transfer and thus enhance the photocatalytic activity. The H 2 evolution rate of optimal NM@NHM hetero-framework can reach 2.25 mmol g - 1 h - 1 under visible light, much higher than pristine NM (0.726 mmol g - 1 h - 1 ) and NHM (1.27 mmol g - 1 h - 1 ). Such high performance can be attributed to the hetero-framework structure consisting of NM and NHM with similar composition and structure, which reduces the interfacial resistance in the charge transfer, thus facilitating the photocatalytic H 2 evolution. Our work may provide a new strategy for the rational design of high -performance photocatalysts.